This invention relates generally to integrating computers and telephones, and in particular to enhancing the call control information associated with a phone for the purpose of such integration.
Many individuals have a telephone and a computer on their office desktops today. Efforts have been made to functionally integrate the two devices to leverage the strengths of each. One such effort has been through the use of computer telephony integration (CTI). CTI allows a computer and a telephone switch to exchange telephone call control information. One benefit of CTI is to allow call control to move from a telephone set to the personal computer screen, mouse, and keyboard. This not only offers users more flexible call functions and status information, it also enables the telephone to become a logical extension of desktop applications and functions for intelligent, personalized call and voice message management. However, CTI is frequently available only to large entities that are in a position to negotiate a large contract with a telephone company, or purchase its own private branch exchange (PBX). Even in those relatively rare instances where CTI is more widely available, administrative and capacity issues frequently prevent companies from being able to deploy CTI.
Telephone sets communicate using either digital or analog signaling. One type of digital telephone technology is Integrated Services Digital Network (ISDN). ISDN technology features a robust call control message set, referred to as Q.931 messages, that can be used by an ISDN modem or telephone. One advantage to using digital signaling, such as Q.931 messaging, is the increased information available during the call setup process. Unfortunately, ISDN has not been widely successful in the United States due to cost and other factors, and consequently the majority of telephones currently in existence are analog telephones. In contrast to an ISDN telephone, only limited call control functionality is associated with an analog telephone. The limited call control information associated with an analog telephone limits the ability to integrate a computer and a telephone.
Given the large number of individuals that have an analog telephone and computer on their desktop, it would be desirable if a method and system were available to enhance the call control information associated with an analog telephone. Such enhanced call control information would allow tighter integration between the telephone and computer than is currently feasible.
In accordance with the purposes of the present invention, a method and system for communicating a call control message between a loop interface device and a computer is provided. An analog telephone is provisioned at a switch as an ISDN telephone. Communications between the telephone and the switch are processed through a loop interface device. The loop interface device receives a first ISDN message transmitted by the switch to the telephone. The loop interface device forwards notification of the first ISDN message to a computer associated with the telephone. In response to the first ISDN message, the computer can generate and send to the loop interface device a second ISDN message. The loop interface device receives the second ISDN message and sends it to the switch. The second ISDN message could be, for example, a CONNECT message for establishing communications between the calling and called parties.
According to the present invention, a loop interface device translates ISDN messages received from a switch into the appropriate analog signals for an analog telephone, and maps the ISDN D-channel messages into a suitable format for transmission to a computer associated with the telephone. The loop interface device also receives analog signals from the analog telephone and converts the analog signals into appropriate ISDN messages for transmission to the switch. The loop interface device also maps messages received from the computer into D-channel messages for transmission to the switch.
According to another aspect of the present invention, a method for communicating a call control message between a loop interface device and a computer is provided by indicating to a switch associated with a stimulus messaging device that the stimulus messaging device communicates via a functional messaging protocol, communications between the stimulus messaging device and the switch being processed through the loop interface device. The loop interface device receives a first functional message transmitted by the switch, the first functional message being associated with the stimulus messaging device. Notification of the first functional message is sent to a computer associated with the stimulus messaging device. The computer can utilize the information in the notification to cause processing to occur on the computer, and can respond to the loop interface device with an appropriate call control message, if desired.
Still other advantages of the present invention will become apparent to those skilled in the art from the following description wherein there is shown and described preferred embodiments of this invention. As will be realized, the invention is capable of other different aspects, all without departing from the invention. Accordingly, the drawings and description will be regarded as illustrative in nature and not as restrictive.